1311431389 has 2 divisors, whose sum is σ = 1311431390. Its totient is φ = 1311431388.

The previous prime is 1311431321. The next prime is 1311431399. The reversal of 1311431389 is 9831341131.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1311164100 + 267289 = 36210^2 + 517^2 .

It is an emirp because it is prime and its reverse (9831341131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1311431389 - 2⁹ = 1311430877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311431399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655715694 + 655715695.

It is an arithmetic number, because the mean of its divisors is an integer number (655715695).

Almost surely, 2^1311431389 is an apocalyptic number.

It is an amenable number.

1311431389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311431389 is an equidigital number, since it uses as much as digits as its factorization.

1311431389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 1311431389 is about 36213.6906293739. The cubic root of 1311431389 is about 1094.5825612879.

The spelling of 1311431389 in words is "one billion, three hundred eleven million, four hundred thirty-one thousand, three hundred eighty-nine".